And the Pharisees came forth—St. Matthew (Matthew 16:1) says that the Sadducees came with them—and began to question with him, seeking of him a sign from heaven, tempting him. They had already asked for a sign from heaven (Matthew 12:38); but now this miracle gives them occasion to ask again.
For when they saw how greatly it was extolled by the multitudes who had benefited by it, it was easy for them to urge that it was an earthly sign, and might have been wrought by him who is called "the God of this world;" and so they insinuated that he had wrought this miracle as well as his other miracles by the power of Satan.
Therefore they seek a sign from heaven, that he who dwells in heaven might thus bear witness that he came from God, and that his doctrine was Divine; the Pharisees probably meant that if he did this they would believe in him as the Messiah, and lead the people to the same faith.
The Sadducees, who were practically atheists, thought that no sign could be given from heaven by God, seeing that in their opinion it was doubtful whether there was any God to give it.